The Romance languages, with the exception of French, admit two ways of expressing indefiniteness in the plural, the bare plural (- N) or the plural introduced by a special determiner (Det N). We show that Det N is selected when reference is made to particulars, as opposed to mere categorization by naming the species, the latter being indicated by means of the bare plural. We are then left with the paradox that Det N is the form normally showing up in metaphorical expressions after the copula, a typically non referential position. We argue that this peculiar behaviour is due to the fact that Det N is basically a form of quantification whereas the property of referentiality is derived and contextually bound.